The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Mechanical joints between sections of metallic tubing are necessary in order to provide for ease of joining during assembly of high pressure gas lines. For applications involving gas temperatures less than 1300° F., sections can be joined using metal fittings that rely on elastic deflection of internal sealing surfaces. Such “dynamic seal” fittings cannot be used at temperatures above 1300° F. because the internal sealing surfaces plastically deform and permanently set into their deflected shape, loosing their elasticity and ability to provide a leak-free seal.
To achieve leak-free joints in high temperature (i.e., above 1300° F.) pressurized gas lines, it has typically been necessary to resort to fusion welding. Use of conventional fusion welding operations to join tube segments requires sufficient 360° access to the full circumference of the tube joint to accommodate manual or automated orbital fusion welding equipment. In applications that require dense packing to conserve volume and minimize weight, providing such access often results in suboptimum packing designs that unduly penalize the performance of end items that are weight and/or size critical. Examples of end items where low weight and size are critical include high performance aircraft and high performance missile systems and propulsion systems such as turbine engines.
In one aspect the present disclosure relates to a method for forming a fluid tight seal. The method may comprise providing a first component having a first sealing surface, and providing a second component having a second sealing surface. The method may further comprise coating one of the first and second sealing surfaces with a metallic film layer adapted to transform into a liquefied metallic layer when a temperature of one of the first and second sealing surfaces exceeds a melting temperature of a metal used to form the metallic film layer. The liquefied metallic layer helps to form a pressure-tight seal between the sealing surfaces.
In another aspect the present disclosure relates to a method for forming a dynamic beam seal coupling device. The method may comprise providing a first tubular component having a first, generally planar sealing surface. A second tubular component having a second, generally planar sealing surface may also be provided. The first and second sealing surfaces may be arranged on their respective first and second tubular components such that the first and second sealing surfaces are in a facing relationship with one another when the first and second tubular components are coupled together. A metallic film layer may be applied to one of the first and second sealing surfaces. The metallic film layer may exist in a solid state prior to a pressurized, heated fluid of at least about 500 psi being flowed through the first and second tubular components. The metallic film layer may transform into a liquefied metal layer when the metallic film layer is exposed to the pressurized, heated fluid, and wherein the pressurized, heated fluid has a temperature that exceeds a melting temperature of a metal from which the metallic film layer is formed. The liquefied metal layer forms a liquid seal between the sealing surfaces while the metallic film layer is maintained in a liquefied state by heat from the pressurized, heated fluid.
In still another aspect the present disclosure relates to a method for forming a dynamic beam seal that is effected upon exposure to a pressurized, heated fluid having a pressure of at least about 500 pounds per square inch. The method may comprise providing a first tubular component having a first sealing surface, and providing a second tubular component having a second sealing surface. The first and second sealing surfaces may be arranged on their respective first and second tubular components such that the first and second sealing surfaces are in a facing relationship with one another when the first and second tubular components are coupled together. A metallic film layer may be applied to one of the first and second sealing surfaces. The metallic film layer may exist in a solid state prior to the pressurized, heated fluid being flowed through the first and second tubular components. The metallic film layer may transform into a liquefied metal layer when the metallic film layer is exposed to the pressurized, heated fluid having a temperature that exceeds a melting temperature of a metal from which the metallic film layer is formed. The metallic film layer may further be provided with a thickness greater than about 0.001 inch and up to about 0.002 inch, prior to the metallic film layer transforming into the liquefied metal layer.